Apparatus is known for scanning photographic color film negatives or transparencies in a plurality of individual component colors. Commonly assigned U.S. Pat. No. 5,153,715 discloses such an apparatus in which a solid state image scanning array comprises a plurality of parallel linear array sensors which are aligned with a scan aperture and exposed directly to an image projected from a film negative or transparency positioned at a film plane at the scan aperture, without the need for any optical features such as lenses or beam splitters between the film and the sensors. The sensors are in near or virtual contact with the film, there being typically only about, 2.5 mm spacing between the two. With a typical cover glass for such array sensors being about 0.65 mm thick, a very narrow passage about 1.0 mm wide remains between the cover glass and the film. The output from the sensor array can be used in a digital printer to produce so-called index prints including small imagettes of the images on a filmstrip, to produce larger prints digitally, or to adjust the color balance of a conventional optical photographic printer to produce conventional photographic prints.
Although the apparatus disclosed in the commonly assigned patent functions admirably for making index prints and for adjustment of color balance, problems can arise when larger digital prints are made, due to accumulation of debris on the cover glass of the sensor array. Accumulations of debris which do not appreciably influence making of index prints or adjusting of color balance can become quite visible on a larger digital print. So, a need has developed for an apparatus for cleaning such a cover glass during operation of the scanner.